Method of enhancing filling power, etc., of landfowl feathers with hydrosulfide compounds and products produced thereby



United States Patent Ofifice 2,857,237 Patented Oct. 21, 1958 IVIETHOD F ENHANCING FILLING POWER, ETC,

OF LANDFOWL FEATHERS WITH HYDROSUL- FIDE COMPOUNDS AND PRODUCTS PRO- DUCED THEREBY Edward R. Frederick and Michael C. Jaskowski, Pittsburgh, Pa., assignors t0 the United States of America as represented by the Secretary of the Army No Drawing. Application March 20, 1953 Serial No. 343,806

Claims. (Cl. 8-94.10)

This application is a continuation-in-part of our application Serial No. 305,076 filed August 18, 1952, now abandoned.

This invention relates to the treatment of chicken feathers and other land fowl feathers to enhance their filling power, remove odors and odor-creating natural oils and waxes, destroy vermin, and make a resilient mat or batt suitable without additional expensive processing for use as a filler for cushions, an insulating layer for sleeping bags, a liner for cold weather clothing, and similar purposes.

In explanation of the term filling power, reference may be made to the report entitled A Proposed Method for Measuring the Filling Power of Down and Feathers by Henry A. Sinski, publication No. TD 103037, The Oflice of Technical Services, U. S. Department of Commerce, and to the article by N. B. Edelman in Textile Research Journal, vol. 17, p. 199 (1947) entitled Investigation of Methods for Determining the Filling Power of Feathers. See also the patent to Sinski et al. No. 2,706,910 dated April 26, 1955. r

In accordance with the invention, we take one pound of straight chicken feathers, fractionated, preferably not over 3 /2 in. long, and first clean them by washing with a detergent mix. Washing may be done in any ordinary power-driven washing machine. One such mix from which excellent results were obtained was composed of- Gm. Tergitol NPX 27.3 Naccanol NR 68.3 Metso No. 55 27.3

Total 122.9

Tergitol NPX is a trade name of the Carbide & Chemicals Corporation for a non-ionic oil-solubilizing detergent. Naccanol NR is an anionic alkyl aryl sulfonate, a detergent of 40% concentrationsold by the National Anilin Division of the Allied Chemical & Dye Corporation. Another alkyl aryl sulfonate also suitable for use in the mix is sold under the trade name Regal by Armour & Co. Metso No. 55 is a trade name for sodium metasilicate (Na SiO sold by the Philadelphia Quartz Co. Obviously water glass of other origin may be used. The above detergent mix plus 98 gm. of Cities Service Solvent No. 21 were mixed in 49 liters of hot water. Then the straight feathers were added and the mixture agitated for one half an hour. Finally the feathers were rinsed and spun centrifugally to remove nearly all the detergent.

The washed but still damp batch of feathers was then placed in an insulated vessel containing a 5% by weight solution of sodium hydrosulfide or sulfhydrate (NaSH) at a temperature of 120 F. and allowed to remain for 18 hours, at which time the temperature had dropped to 105 F. Then the feather batch was rinsed and spun as before to remove the chemical and was picked, dried, treated with an oxidizing agent, and fluffed in the machine of the Frederick, Jaskowski and Haller Patent No.

2,739,391 dated March 27, 1956. The NaSl-I attacked the quills and shafts, making them brittle and in some instances completely separating the fibers or barbs from the quills and shafts. These loose pieces could be removed by air' currents, as will be understood by those skilled in the art of feather handling. The fibrous mat or batt resulting from the described procedure was fluffy, resilient and coherent, and had a coarse feel much like the feel of wool. by Sinskis apparatus was 4.7 cm.; with the cylinder walls of said apparatus wetted to eliminate static electricity, the filling power reading was 4.5 cm. Since straight chicken feathers have a filling power of 1.9 to 2.0 cm. or thereabouts, it is clear that the described procedure increased the filling power by more than 100%, besides affording other advantages, such as materially lowering the cost of feather treatment.

In another procedure within the scope of our invention, one pound of straight unwashed chicken feathers were immersed in 7 liters of hot water containing 5% by weight of NaSH, and filling power readings were taken at various intervals with the results shown in the following table, taken from page 55 of Notebook N (Mellon Institute of Industrial Research).

TABLE Time of Tempera- Sample Immersion cure of sol. F.P

(hours) F.)

'4.0 5 E2 (w) 24 80.6 hifi 24 80.6 4:30)

Sample D of the above table, after rinsing and wringing, was further treated by immersion in a dilute solution of hydrogen peroxide, and then Was dried and flutfed. Samples A, B, C and E, after rinsing and wringing, were each dried and fluifed in the machine of said Frederick et a1. Patent No. 2,739,391 while exposed to an ozone atmosphere to effect oxidation.

In the above table, the first filling power reading for each sample was by the standard Sinski procedure, the second, designated (w), was taken with the cylinder walls of Sinskis apparatus wetted to eliminate static. It will be noted by comparing the first and last readings of filling power that there was practically the same increase in filling power at the end of 2 hours at a slightly elevated temperature as after 24 hours immersion at approximately room temperature. The filling power readings of the above table, when compared with the filling power values previously given (4.7 and 4.5) show that unwashed feathers had nearly the same filling power, after treatment, as washed treated feathers.

Although the filling power values of sample A (immersed for 2 hours) and samples D or E (immersed for 24 hours) are essentially the same, the physical properties of the products which in turn accounts for the reasonably high bulk filling capacities are quite different. During the early stages of the digestion process, the appearance of the feathers is not appreciably changed from that of straight run feathers. The most significant differences are (1) increased stiffness of the quill or vane in the treated feather, and (2) apparent fixation of the curl that develops during processing. To understand these changes, it is necessary to consider our hypothesis of the reactions that occur during NaSH treatment.

The filling power of the product as measured- NaSH solutions are alkaline and have reducing properties.

The protein structure of the various parts of chicken feathers are not identical. The simpler proteins are more easily attacked than the larger molecules. From observations of the relative solubility of the feather portions in caustic solutions, the following order of decreasing solubility is given approximately as follows:

Quill membrane barbulesbarbs quill (In a 5% NaOH solution, all the feather may be dissolved but the last portion to gointo solution is the quill.)

Under reducing conditions, using the NaSH treatment, the reaction is somewhat better controlled inasmuch as the pH is limited to inhibit serious attack on any other than the more sensitive portions of the feather. Thus, even after lengthy periods of digestion (24 hours) the barbs are not dissolved but are removed intact from the vane or quill. Thus, one function of the NaSH treatment is its controlled pH to solvate the quill membrane without affecting the barbs. Furthermore, the order of solubility changes in the presence of NaSH and under the conditions of controlled pH provided by the NaSH solution. Under these conditions the order of decreasing solubility for chicken feather parts is:

Quill membrane quill barbules-e barbs Alkalias and reducing agents have other effects on keratin. Both cause breakage at the cystine linkages of the keratin, although alkalis alone require no subsequent oxidation for reformation of the cystine bonds. The use of reducing agents, such as NaSH, causes separation of the disulfide (cystine linkages) actually inactivating the sulfenic acid formed by the splitting operation to inhibit reformation of cross-links until oxidized. The regeneration of cystine linkages is not the same as the original bridging. The new linkages occur between adjacent chains leading to greater stability and, presumably, greater stiffness.

When these changes are brought about while feathers are being processed in the picker and opening system of the feather treating apparatus, the curl that is imparted to the feathers is not only more permanently fixed, but the curled feathers possess more effective bulk properties because of the improved resiliency of the curled feathers.

The solutions that cause these solubilizing and cystine link modifications, alkalis particularly, also assist in promoting curl development in chicken feathers. When keratin fibers are stretched while wet and then allowed to dry unrestrained, they may shrink to as much as 73 their original length. The ability of alkali to increase wettability, together with the stretching of feathers that occurs during laundering and/or picking and the free drying conditions permitted in our feather processing equipment, is believed to account for curl development. If supercontraction does occur during the drying, as is quite likely, then its effect will be manifested on the nonuniform cross-section feather quill by producing significant bending of these parts. This then accounts for the increased bulk filling power of NaSH two-hour digestion period treated feathers, since in addition to promoting curl development, some measure of increased stiffness and permanency is given to these higher bulk feathers.

The feather fibers possess higher bulk properties than ordinary feathers apparently because the heavy quill fraction constitutes a lesser amount of the product, fiber stiffness is materially increased by cystine linkage modification, and the fibers are crimped.

It is preferred to conclude the treatment by subjecting the feather product to an oxidizing agent such as a bath of hydrogen peroxide, or an oxidizing atmosphere, such as that which is created by a Westinghouse ozone lamp operated in a closed vented chamber like the one shown in said Frederick et al. Patent No. 2,739,391. Oxidation should continue for a suflicient time to arrest further serves to saponify natural oils of the feather finish in somewhat of a buffered solution (inhibiting solvation of the barbs) and thereby effects removal of that element of the natural feather finish which prevents satisfactory waxsilica gel treatment.

Straight feathers (product of Northern Feather Works, Newark, N. J.) identified as sample N7 l-b, where treated with a 5% solution of NaSH for 24 hours, at a temperature of 80.6 F. A more complete reaction occurred than in the case of Sample D of the above table. Two pounds of the treated sample, after H 0 oxidation, rinsing and wringing, was treated with a wax plus hydrophobic silica gel finish (as in the E. R. Frederick Patent No. 2,714,561 dated August 2, 1955 and then was dried and fluffed in the previously mentioned machine. The product possessed a wool-like appearance and feel and displayed a tendency to agglomerate.

While the described procedures result in greatly improved products, insofar as filling power measurements are concerned, we consider that a 5% solution of NaSH (or its equivalents) is undesirable for a commercial process, because NaSH of that concentration readily attacks metal pipes and other equipment, creates a problem of disposal of used liquor, is too expensive, and results in aproduct which is brittle, so that its useful life as a filling material for sleeping bags, etc. may not be as long as is desirable. Lower concentrations of sodium hydrosulfide have therefore been used, with excellent results.

Thus to one-half pound of straight dry chicken feathers we added a solution made up as follows, held at room- Soaking may continue for nine days or even longer. The gentle reaction of this very dilute solution produces a soft non-brittle fiber, which is desirable for many purposes. For a more rapid reaction, a solution may be made of 10 gm. sodium hydrosulfide, with 10 gm. of dimethylamine sulfate, 20 gm. of Ca(OH) and water to make 3000 gm. The soaking in this solution will take not over five days and the product will be more brittle than is the case with the solution containing 0.03% by weight of sodium hydrosulfide.

The nature of the action of the dimethylamine sulfate is obscure: it differs from the action of the sodium hydrosulfide in that it seems to retard embrittlement of the feather fibers produced by the sodium hydrosulfide. The dimethylamine sulfate does not attack the feather fibers but apparently accelerates the lime and sodium hydrosulfide reactivity without the need for a high pH, making possible the employment of low lime and sulfide concentrations as just described. This makes for economy and minimizes concentrations of the reagents in the by-product or waste liquor.

Generally speaking, the concentration of the sodium hydrosulfide may range from 0.03% to 5.0% by weight,

our

and the dimethylamine sulfate should equal the weight of the sodium hydrosulfide.

In lieu of sodium hydrosulfide, we may employ the more expensive and therefore less desirable potassium hydrosulfide KSH, whose action is practically the same, or ammonium hydrosulfide NHqSH may be used.

In the above description and in the subjoined claims for convenience we use the expression feather product to denote chicken feathers, fractionated turkey and other land fowl feathers whether straight or crushed, also feather fibers and stripped feathers, also mixtures in various proportions of land fowl feathers, feather fibers, crushed feathers and stripped feathers. Waterfowl feathers and down and mixtures thereof are disclaimed.

What we claim is:

1. A method of treating land fowl feathers to enhance their filling power, remove odors and odor-creating content, destroy vermin and make a resilient batt suitable for use as a filler or heat-insulating layer, which essentially consists of immersing said land fowl feathers in a dilute aqueous solution selected from the group consisting of potassium, ammonium and sodium hydrosulfide solutions of from about .03% to about 5% concentration, the pH of said solution being sufficiently low to avoid damage to the feather barbs; agitating the solution; continuing the immersion at a temperature not substantially less than room temperature until the filling power of the feathers is increased; removing the feathers from said solution after at least about two hours, and rinsing and drying them.

2. A method of treating land fowl feathers to enhance their filling power, remove odors and odor-creating content, destroy vermin and make a resilient batt suitable for use as a filler or heat-insulating layer, which essentially consists of immersing said land fowl feathers in an about 5% aqueous solution of sodium hydrosulfide, the pH of said solution being sufficiently low to avoid damage to the feather barbs; agitating the solution; continuing the immersion at a temperature not substantially less than room temperature until the filling power of the feathers is increased; removing the feathers from said solution after at least about two hours, rinsing the feathers, subjecting them to oxidation by treatment with an oxidizing agent being a member of the group consisting of peroxide and ozone, and drying them.

3. A method of treating land fowl feathers to enhance their filling power, remove odors and odor-creating content, destroy vermin and make a resilient batt suitable for use as a filler or heat-insulating layer, which essentially consists of immersing said land fowl feathers in an aqueous solution of approximately 0.03% sodium hydrosulfide, approximately 0.03% dimethylamine sulfate and approximately 0.67% hydrated lime, the pH of said solution being sufficiently low to avoid damage to the feather barbs; continuing the immersion at a temperature not sub- .6. stantially less than room temperature until the filling power of the feathers is increased; removing the feathers from said solution after about nine days, and rinsing and drying them.

4. A method of treating land fowl feathers to enhance their filling power, remove odors and odor-creating content, destroy vermin and make a resilient batt suitable for use as a filler or heat-insulating layer, which essentially consists of immersing said land fowl feathers in an aqueous solution of about 0.33% sodium hydrosulfide, about 0.33% dimethylamine sulfate and about 0.67% hydrated lime, the pH of said solution being sufficiently low to avoid damage to the feather barbs; continuing the immersion at a temperature not substantially less than room temperature until the filling power of the feathers is increased; removing the feathers from said solution after about five days, and rinsing and drying them.

5. A method of treating land fowl feathers to enhance their filling power, remove odors and odor-creating content, destroy vermin and make a resilient batt suitable for use as a filler or heat-insulating layer, which essentially consists of immersing said land fowl feathers in an aqueous solution of sodium hydrosulfide of from about .03% to about 5% concentration, the pH of said solution being sufficiently low to avoid damage to the feather barbs; continuing the immersion at a temperature not substantially less than room temperature until the filling power of the feathers is increased; removing the feathers from said solution after an immersion time of from about two hours to about nine days; rinsing the feathers, treating with an oxidizing agent being a member of the group consisting of peroxide and ozone, and drying them.

6. The product produced by the method of claim 1.

7. The product produced by the method of claim 2.

8. The product produced by the method of claim 3.

9. The product produced by the method of claim 4.

10. The product produced by the method of claim 5.

References Cited in the file of this patent UNITED STATES PATENTS 2,068,809 Maeder Jan. 26, 1937 2,201,929 Speakman May 21, 1940 2,406,958 McQueen Sept. 3, 1946 2,447,860 Jones et al. Aug. 24, 1948 FOREIGN PATENTS 118,651 Australia June 22, 1944 333,197 Great Britain Aug. 5, 1930 OTHER REFERENCES Marriott, R. H.: The Unhairing Action of Amines, Stiasny-Festschrift, 1937, pp. 245250.

I ones et al.: Dispersion of Keratins, Arch. of Bio- 0 chem., vol. 2, 1943, pp. 209-223. 

1. A METHOD OF TREATING LAND FOWL FEATHERS TO ENHANCE THEIR FILLING POWER, REMOVE ODORS AND ODOR-CREATING CONTENT, DESTROY VERMIN AND MAKE A RESILIENT BATT SUITABLE FOR USE AS A FILLER OR HEAT-INSULATING LAYER, WHICH ESSENTIALLY CONSISTS OF IMMERSING SAID LAND FOWL FEATHERS IN A DILUTE AQUEOUS SOLUTION SELECTED FROM THE GROUP CONSISTING OF POTASSIUM, AMMONIUM AND SODIUM HYDROSULFIDE SOLUTIONS OF FROM ABOUT .03% TO ABOUT 5% CONCENTRATION, THE PH OF SAID SOLUTION BEING SUFFICIENTLY LOW TO AVOID DAMAGE TO THE FEATHER BARBS; AGITATING THE SOLUTION; CONTINUING THE IMMERSION AT A TEMPERATURE NOT SUBSTANTIALLY LESS THAN ROOM TEMPERATURE UNTIL THE FILLING POWER OF THE FEATHERS IS INCREASED; REMOVING THE FEATHERS FROM SAID SOLUTION AFTER AT LEAST ABOUT TWO HOURS, AND RINSING AND DRYING THEM. 